CN115647106A - Production method of small-caliber thick-wall titanium alloy seamless pipe - Google Patents
Production method of small-caliber thick-wall titanium alloy seamless pipe Download PDFInfo
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Abstract
The invention provides a production method of a small-caliber thick-wall titanium alloy seamless pipe, which comprises the following steps: the method comprises the following steps: carrying out VAR smelting for the third time to obtain a titanium alloy ingot; step two: cogging, drawing and radially forging a titanium alloy ingot into a round bar, and processing the round bar into a hollow pipe blank by deep hole drilling, inner honing and outer turning; step three: carrying out three times of cold rolling on the hollow pipe blank to prepare a finished product of the titanium alloy seamless pipe; sampling the titanium alloy pipe after each cold rolling, observing the crack defect of the titanium alloy pipe, removing the crack defect, and performing intermediate vacuum annealing after removing the crack defect; step four: and (4) carrying out vacuum annealing, straightening, acid washing, ultra-probing and packaging on the titanium alloy finished pipe obtained in the step three to obtain the small-caliber thick-wall titanium alloy seamless pipe. The invention comprehensively sets measures from the aspects of specification design of the tube blank, processing technology of the tube blank, cold rolling technology design of the titanium alloy tube, design of the vacuum annealing technology, defect treatment technology of the inner surface and the outer surface of the tube blank and the like, and solves the problem of the inner surface cracks of the cold rolling of the small-caliber thick-wall titanium alloy seamless tube.
Description
Technical Field
The invention relates to the technical field of preparation of non-ferrous metal seamless pipes, in particular to a production method of a small-caliber thick-wall titanium alloy seamless pipe.
Background
The titanium alloy has poor plasticity, cold rolling texture and strong anisotropy, so that the titanium alloy tube is easy to have poor dimensional precision and internal and external surface defects in cold rolling.
For a small-caliber thick-wall titanium alloy seamless pipe with the outer diameter of less than or equal to 10mm, the wall thickness of more than or equal to 1mm and the outer diameter-wall thickness ratio of less than or equal to 5.5, because the inner surface of the titanium alloy pipe is easy to crack in the cold rolling process due to the influence of specifications, products are scrapped, and the existing preparation method has no perfect solution.
Disclosure of Invention
According to the technical problem, the method for producing the small-caliber thick-wall titanium alloy seamless pipe is provided. The invention comprehensively makes measures from the aspects of pipe blank specification design, pipe blank processing technology, titanium alloy pipe cold rolling technology design, vacuum annealing technology design, pipe blank inner and outer surface defect treatment technology and the like, and solves the problem of small-caliber thick-wall titanium alloy seamless pipe cold rolling inner surface cracks.
The technical means adopted by the invention are as follows:
a production method of a small-caliber thick-wall titanium alloy seamless pipe comprises the following steps:
the method comprises the following steps: carrying out VAR smelting for the third time to obtain a titanium alloy ingot;
step two: the titanium alloy ingot is processed by 5 times of fire, three piers and three decollements to form a square billet, 1 time of fire to form a long rod, and 3 times of fire, radial forging is carried out to form a round rod, and the radial forging temperature is 840-850 ℃. The round bar meets the requirement of flaw detection to reach the AA level of GB/T5193 standard, the round bar is processed into a hollow tube blank with the outer diameter of D and the wall thickness of S through deep hole drilling, inner honing and outer lathing, and the outer diameter-wall thickness ratio (D/S) is less than or equal to 5.5; the inner honing adopts green carborundum oilstone with W40 granularity bonded by resin bonding agent, the working pressure is 1.3Mpa, the honing speed is 18-21 m/min, and the roughness after honing in the hollow pipe blank is less than or equal to 0.4 micron.
Step three: carrying out three times of cold rolling on the hollow pipe blank to prepare a finished titanium alloy seamless pipe product with the outer diameter of D1 and the wall thickness of S1; the wall thickness S of the hollow pipe blank is 3 times of the wall thickness S1 of the finished titanium alloy seamless pipe;
the deformation rate epsilon and the K value of each cold rolling pass in the cold rolling process are smaller than those of the previous cold rolling pass, and the K value of each cold rolling pass is more than or equal to 1; the titanium alloy pipe with the outer diameter Da and the wall thickness Sa is cold-rolled into a titanium alloy pipe with the outer diameter Db and the wall thickness Sb for one pass, and the deformation rate epsilon of the cold rolling for the pass is calculated by the following formula:
ε＝((Da-Sa)×Sa-(Db-Sb)×Sb)/((Da-Sa)×Sa)；
the calculation formula of the K value of the pass cold rolling is as follows: k = (Sa-Sb) × Da/(Da-Db) × Sa.
The MoS with the fineness of 900 meshes is rolled before each cold rolling 2 Paraffin and No. 32 antiwear engine oil are mixed according to the proportion of 1:1: the rolling lubricating oil mixed in the weight ratio of 8 is coated on the inner surface of the titanium alloy pipe and the surface of the core rod, the lubricating oil of a rolling mill is filtered before and during each cold rolling, and the filtering precision reaches 3 microns.
Sampling the titanium alloy pipe after each cold rolling, observing the crack defect of the titanium alloy pipe, and removing the crack defect, wherein the specific mode is as follows: after cold rolling of each pass of the titanium alloy pipe, taking a 100mm long pipe section sample, removing the wall thickness of the pipe section sample by acid washing by 0.01mm, splitting and observing the inner surface and the outer surface, confirming the distribution, the trend and the maximum defect position of crack defects, taking longitudinal and transverse metallographic structure samples at the maximum defect position, determining the maximum depth h of the crack defects and the opening distance for observing the crack defects, removing the crack defects according to the opening distance and the maximum depth h, taking the 100mm long pipe section sample after removing, observing by an image instrument and a stereoscopic microscope to confirm that the inner surface and the outer surface have no defects, and then carrying out intermediate vacuum annealing and next cold rolling on the titanium alloy pipe;
the inner surface defect with the opening distance of the crack defect being more than or equal to 0.02mm is subjected to inner honing to remove the inner surface wall thickness h +0.02mm of the titanium alloy pipe; the inner honing adopts green carborundum oilstone with W40 granularity bonded by resin bonding agent, the working pressure is 1.3Mpa, and the honing speed is 18-21 m/min;
selecting an abrasive belt to remove the wall thickness h +0.02mm of the outer surface of the titanium alloy pipe by outwards polishing the outer surface defect with the opening distance of the crack defect being more than or equal to 0.02mm;
and selecting inner and outer surface flowing acid cleaning for the inner and outer surface defects with the opening distance of the crack defect less than 0.02mm, and removing the wall thickness h +0.02mm of the titanium alloy pipe. The single inner surface flowing acid washing is used for covering the outer surface of the titanium alloy pipe by adopting plastic bags in a bundling manner, and the single outer surface flowing acid washing is used for blocking two end heads of the titanium alloy pipe by adopting plastics; the pickling solution adopts HF acid: HNO 3 Acid: water is added according to the weight ratio of 4:15:81 parts by weight, and flowing through the inner surface and/or the outer surface of the titanium alloy tube at a speed of 3 m/min or more.
After each cold rolling, removing crack defects, and then carrying out intermediate vacuum annealing, wherein the intermediate vacuum annealing process of the titanium alloy pipe with the deformation rate of epsilon and the outer diameter of Db and the wall thickness of Sb is as follows: the temperature rising speed is 2 ℃/min, the intermediate annealing temperature is (600 +300 multiplied by epsilon) DEG C, the heat preservation time is 55 multiplied by Sb minutes, and the elongation of the annealed titanium alloy tube is more than or equal to 30 percent.
Step four: and (3) carrying out vacuum annealing, straightening, acid washing, ultra-probing and packaging on the titanium alloy finished tube obtained in the step three to obtain the small-diameter thick-wall titanium alloy seamless tube with the outer diameter D2 of not more than 10mm, the wall thickness S2 of not less than 1mm and the outer diameter-wall thickness ratio of not more than 5.5. And the vacuum annealing in the fourth step is adjusted according to the performance requirement of a preset product.
Compared with the prior art, the invention has the following advantages:
according to the invention, the three-time VAR smelting ensures uniform components of the titanium alloy; the thermal deformation process combination of three-drawing cogging with 5 fire, three-drawing cogging with 1 fire, and 3-heating radial forging at 840-850 ℃ ensures that the titanium alloy round bar has uniform structure, uniform performance and good plasticity, the elongation is more than or equal to 28%, the round bar can reach the AA grade of GB/T5193 standard when detecting flaws, and the probability of defects in cold rolling of the titanium alloy pipe is reduced; the hollow pipe blank is manufactured by adopting deep hole drilling, inner honing and outer turning machining, so that the defects of the inner surface and the outer surface of the pipe blank are completely avoided; the optimized inner honing process ensures that the roughness of the inner surface of the hollow pipe blank is less than or equal to 0.4 micron, and reduces the probability of defects on the inner surface of the cold-rolled titanium alloy pipe; the method is characterized in that a tube blank is machined at the same time, the specification of the tube blank can be flexibly machined according to the size and specification of a finished tube so as to conveniently design a cold rolling process, a hollow tube blank with the outer diameter-wall thickness ratio of less than or equal to 5.5 is machined, the wall thickness S is 3 times of the wall thickness S1 of the finished titanium alloy tube, the K value of each cold rolling from the tube blank to the finished tube is more than or equal to 1, and the K value of the cold rolling more than or equal to 1 is a necessary condition for ensuring that no crack occurs on the cold-rolled inner surface of the titanium alloy tube; before cold rolling, lubricating oil is coated on the inner surface of the titanium alloy pipe and the surface of the core rod, so that the lubrication of the inner surface of the titanium pipe in the cold rolling process is enhanced, and the probability of cold rolling defects is reduced; the lubricating oil of the rolling mill is kept clean through filtering, so that the cold rolling defect caused by impurities in the oil is avoided; the vacuum annealing temperature is determined according to the cold rolling deformation of the titanium alloy pipe, the heat preservation time is determined according to the wall thickness of the titanium alloy pipe, the on-site annealing process not only realizes complete recrystallization, but also avoids the growth of crystal grains, and ensures the optimal plasticity of the titanium pipe, thereby reducing the probability of cold rolling defects to the maximum extent; the method for observing the defects of the inner surface and the outer surface of the titanium tube and the combined treatment process of the defects of the inner surface and the outer surface completely eliminate the defects possibly generated by the previous cold rolling, and avoid the rejection of the titanium tube caused by the fact that the defects are continuously expanded when being transmitted to the next cold rolling; for the crack defect with large opening distance of the defect, the crack defect cannot be removed by adopting the flowing acid washing, and only can be removed by adopting the methods of inner honing grinding and outer abrasive belt polishing, and for the defect of the inner surface and the outer surface with the opening distance of the defect less than 0.02mm, acid liquor cannot enter the defect due to the small opening distance, so the defect can be removed by the flowing acid washing.
Based on the reason, the invention can be widely popularized in the fields of small-caliber thick-wall titanium alloy seamless pipe production and the like.
Detailed Description
It should be noted that the embodiments and features of the embodiments may be combined with each other without conflict. The present invention will be described in detail with reference to examples.
It should be apparent that the described embodiments are only some embodiments of the present invention, and not all embodiments. The following description of at least one exemplary embodiment is merely illustrative in nature and is in no way intended to limit the invention, its application, or uses. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
The invention provides a production method of a small-caliber thick-wall titanium alloy seamless pipe, which comprises the following steps:
the method comprises the following steps: carrying out VAR smelting for the third time to obtain a titanium alloy ingot;
step two: the titanium alloy ingot is processed by 5 times of fire, three piers and three decollements to form a square billet, 1 time of fire to form a long rod, and 3 times of fire, radial forging is carried out to form a round rod, and the radial forging temperature is 840-850 ℃. The round bar meets the requirement that the flaw detection reaches the AA level of GB/T5193 standard, the round bar is processed into a hollow tube blank with the outer diameter of D and the wall thickness of S through deep hole drilling, inner honing and outer turning, and the ratio of the outer diameter to the wall thickness is less than or equal to 5.5; the inner honing adopts green carborundum oilstone with W40 granularity bonded by resin bonding agent, the working pressure is 1.3Mpa, the honing speed is 18-21 m/min, and the roughness after honing in the hollow pipe blank is less than or equal to 0.4 micron.
Step three: carrying out three times of cold rolling on the hollow pipe blank to prepare a finished titanium alloy seamless pipe product with the outer diameter of D1 and the wall thickness of S1; the wall thickness S of the hollow pipe blank is 3 times of the wall thickness S1 of the finished titanium alloy seamless pipe;
the deformation rate epsilon and the K value of each cold rolling pass in the cold rolling process are smaller than those of the previous cold rolling pass, and the K value of each cold rolling pass is more than or equal to 1; the titanium alloy pipe with the outer diameter Da and the wall thickness Sa is cold-rolled into a titanium alloy pipe with the outer diameter Db and the wall thickness Sb for one pass, and the deformation rate epsilon of the cold rolling for the pass is calculated by the following formula:
ε＝((Da-Sa)×Sa-(Db-Sb)×Sb)/((Da-Sa)×Sa)；
the calculation formula of the K value of the pass cold rolling is as follows: k = (Sa-Sb) × Da/(Da-Db) × Sa.
The MoS with the fineness of 900 meshes is rolled before each cold rolling 2 Paraffin and No. 32 antiwear engine oil are mixed according to the proportion of 1:1: the rolling lubricating oil mixed according to the weight ratio of 8 is coated on the inner surface of the titanium alloy tube and the surface of the core rod, the lubricating oil of the rolling mill is filtered before and during each cold rolling, and the filtering precision reaches 3 micrometers.
Sampling the titanium alloy pipe after each cold rolling, observing the crack defect of the titanium alloy pipe, and removing the crack defect, wherein the specific mode is as follows: after cold rolling of each pass of the titanium alloy pipe, taking a 100mm long pipe section sample, removing the wall thickness of the pipe section sample by acid washing by 0.01mm, splitting and observing the inner surface and the outer surface, confirming the distribution, the trend and the maximum defect position of crack defects, taking longitudinal and transverse metallographic structure samples at the maximum defect position, determining the maximum depth h of the crack defects and the opening distance for observing the crack defects, removing the crack defects according to the opening distance and the maximum depth h, taking the 100mm long pipe section sample after removing, observing by an image instrument and a stereoscopic microscope to confirm that the inner surface and the outer surface have no defects, and then carrying out intermediate vacuum annealing and next cold rolling on the titanium alloy pipe;
the inner surface defect with the opening distance of the crack defect being more than or equal to 0.02mm is subjected to inner honing to remove the inner surface wall thickness h +0.02mm of the titanium alloy pipe; the inner honing adopts green carborundum oilstone with W40 granularity bonded by resin bonding agent, the working pressure is 1.3Mpa, and the honing speed is 18-21 m/min;
selecting an abrasive belt to remove the wall thickness h +0.02mm of the outer surface of the titanium alloy pipe by outwards polishing the outer surface defect with the opening distance of the crack defect being more than or equal to 0.02mm;
and selecting inner and outer surface flowing acid cleaning for the inner and outer surface defects with the opening distance of the crack defect less than 0.02mm, and removing the wall thickness h +0.02mm of the titanium alloy pipe. The single inner surface flow pickling adopts plastic bags to cover the outer surface of the titanium alloy pipe in a bundling manner, and the single outer surface flow pickling adopts plastic to block two end heads of the titanium alloy pipe; the pickling solution adopts HF acid: HNO 3 Acid: water is added according to the weight ratio of 4:15:81 weight percent, and flowing through the inner surface and/or the outer surface of the titanium alloy pipe at a speed of more than or equal to 3 m/min.
After each cold rolling, removing crack defects, and then carrying out intermediate vacuum annealing, wherein the intermediate vacuum annealing process of the titanium alloy pipe with the deformation rate of epsilon and the outer diameter of Db and the wall thickness of Sb is as follows: the temperature rising speed is 2 ℃/min, the intermediate annealing temperature is (600 +300 multiplied by epsilon) DEG C, the heat preservation time is 55 multiplied by Sb minutes, and the elongation of the annealed titanium alloy tube is more than or equal to 30 percent.
Step four: and (4) carrying out vacuum annealing, straightening, acid washing, ultra-probing and packaging on the titanium alloy finished pipe obtained in the step three to prepare the small-diameter thick-wall titanium alloy seamless pipe with the outer diameter D2 of not more than 10mm, the wall thickness S2 of not less than 1mm and the outer diameter-wall thickness ratio of not more than 5.5.
Example 1
The TA16 titanium alloy seamless tube with the specification of phi 9 multiplied by 1.7mm is produced, and the ratio of the outer diameter to the wall thickness is 9/1.7=5.294.
The adopted production process flow comprises the following steps: three times of vacuum consumable VAR smelting into phi 490 round TA16 titanium alloy cast ingot → a forging machine 5 times of fire three times of pier three times of free forging into 210 square billet → a forging machine 1 time of fire drawing into phi 160 long round rod → 3 times of fire radial forging into phi 29 black skin round rod → a deep hole drill, an inner honing mill and an outer lathing machine are processed into phi 22 x 5.1 hollow tube blank (the outer diameter wall thickness ratio is 4.3, the wall thickness is 1.7 x 3) → LG15 two-roll cold rolling machine is cold-rolled into phi 16 x 3.2 titanium tube (the epsilon is 52%, the K value is 1.37) → 100mm tube section sample is taken to find that the inner surface has microcracks with the maximum depth of 0.02mm and the crack opening distance is 0.025mm, the inner surface honing mill is adopted (the W40-granularity green silicon carbide oilstone bonded by resin bonding agent, the working pressure is 1.3MPa, grinding speed 19 meters per minute) to remove the wall thickness of the phi 16 multiplied by 3.2 titanium alloy tube 0.04mm → 756 ℃ (600 +300 multiplied by 0.52), heat preservation 176 (55 multiplied by 3.2) minutes vacuum annealing, straightening → LG10 two-roller cold rolling mill is cold rolled into the phi 12 multiplied by 2.3 titanium alloy tube (epsilon is 46%, K value is 1.13) → taking a 100mm tube section sample to find that the inner surface has 0.02mm microcrack with maximum depth, the crack opening distance is 0.01mm, the phi 12 multiplied by 2.3 titanium alloy tube wall thickness is removed by inner surface flowing acid washing 0.04mm → 738 ℃ (600 multiplied by 0.46), heat preservation 126.5 (55 multiplied by 2.3) minutes vacuum annealing, straightening → 10 two-roller cold rolling mill is formed into the phi 9 multiplied by 1.7 titanium alloy tube (epsilon is 44%, K value is 1.04) → 732 ℃ (300 multiplied by 0.44), heat preservation 93.5 (55 multiplied by 1.7) minutes vacuum annealing, straightening → LG straightening → super packaging.
The TA16 titanium alloy seamless tube with the specification of phi 9 multiplied by 1.7mm prepared by the embodiment has the yield strength of 470Mpa, the tensile strength of 590Mpa and the elongation of 28 percent.
Example 2:
the TA18 titanium alloy seamless tube with the specification of Φ 10 × 1.9mm was produced, and the outer diameter-wall thickness ratio value was 10/1.9=5.263.
The adopted production process flow comprises the following steps: three times of vacuum self-consumption phi 490 circular TA18 titanium alloy cast ingot → forging machine 5 times of fire three-pier three-drawing free forging into 210 square blank → forging machine 1 time of fire drawing to phi 160 long round bar → 3 times of fire diameter forging to phi 29 black skin round bar → gun drill, inner honing grinding, outer lathing to phi 24 x 5.7 hollow tube blank (outer diameter wall thickness ratio 4.21, wall thickness 1.9 x 3) → LG15 two-roll cold rolling mill cold rolling to phi 17 x 3.7 titanium tube (epsilon 53%, K value 1.2) → 100mm tube sample found that there is 0.03mm of maximum depth micro crack and crack opening distance 0.02mm, outer surface sand belt polishing to remove phi 17 x 3.7 titanium tube wall thickness 0.05mm → 759 ℃ (600 x 0.53), heat preservation 203.5 (55 x 3.7) LG vacuum annealing, straightening → straightening to phi 12 x 2.5.5 mm of cold rolling tube blank → 600 x 2mm, straightening to phi 10mm of vacuum straightening, straightening to obtain phi 12 x 2.5 mm, straightening to phi 10mm of cold rolling tube blank (phi 10 mm), straightening to phi 10.5 mm, straightening to obtain phi 10mm of straightening, straightening to phi 10.8.8.8 # titanium tube blank (phi 10 # 3.7) and straightening to obtain phi 10 # 3.8 # of maximum straightening.
The TA18 titanium alloy seamless tube with the specification of phi 10 multiplied by 1.9mm prepared by the embodiment has the yield strength of 570MPa, the tensile strength of 680MPa and the elongation of 25 percent.
Finally, it should be noted that: the above embodiments are only used to illustrate the technical solution of the present invention, and not to limit the same; while the invention has been described in detail and with reference to the foregoing embodiments, it will be understood by those skilled in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some or all of the technical features may be equivalently replaced; and the modifications or the substitutions do not make the essence of the corresponding technical solutions depart from the scope of the technical solutions of the embodiments of the present invention.
Claims (8)
1. The production method of the small-caliber thick-wall titanium alloy seamless pipe is characterized by comprising the following steps of:
the method comprises the following steps: carrying out VAR smelting for the third time to obtain a titanium alloy ingot;
step two: cogging, drawing and radial forging a titanium alloy ingot into a round bar, wherein the round bar meets the AA level of the GB/T5193 standard for flaw detection, the round bar is processed into a hollow tube blank with the outer diameter of D and the wall thickness of S through deep hole drilling, inner honing and outer turning, and the ratio of the outer diameter to the wall thickness is less than or equal to 5.5;
step three: carrying out three times of cold rolling on the hollow pipe blank to prepare a finished titanium alloy seamless pipe product with the outer diameter of D1 and the wall thickness of S1;
sampling the titanium alloy pipe after each cold rolling, observing the crack defect of the titanium alloy pipe, removing the crack defect, and performing intermediate vacuum annealing after removing the crack defect;
the wall thickness S of the hollow pipe blank is 3 times of the wall thickness S1 of the finished titanium alloy seamless pipe;
step four: and (3) carrying out vacuum annealing, straightening, acid washing, ultra-probing and packaging on the titanium alloy finished tube obtained in the step three to obtain the small-diameter thick-wall titanium alloy seamless tube with the outer diameter D2 of not more than 10mm, the wall thickness S2 of not less than 1mm and the outer diameter-wall thickness ratio of not more than 5.5.
2. The production method of a small-caliber thick-wall titanium alloy seamless tube according to claim 1, characterized in that: in the second step, the titanium alloy ingot is subjected to three-pier three-drawing cogging for 5 times of fire to form a square billet, is subjected to drawing growth for 1 time of fire to form a long rod, and is subjected to radial forging for 3 times of fire to form a round rod, wherein the radial forging temperature is 840-850 ℃.
3. The production method of a small-caliber thick-wall titanium alloy seamless tube according to claim 1 or 2, characterized in that: and step two, internally honing the green silicon carbide oilstone with the granularity of W40 bonded by using a resin bonding agent, wherein the working pressure is 1.3Mpa, the honing speed is 18-21 meters per minute, and the roughness of the hollow pipe blank after internal honing is less than or equal to 0.4 micrometer.
4. The production method of a small-caliber thick-wall titanium alloy seamless tube according to claim 1, characterized in that: in the third step, before each cold rolling pass, the MoS with the fineness of 900 meshes is obtained 2 Paraffin and No. 32 antiwear engine oil are mixed according to the proportion of 1:1: the rolling lubricating oil mixed in the weight ratio of 8 is coated on the inner surface of the titanium alloy pipe and the surface of the core rod, the lubricating oil of a rolling mill is filtered before and during each cold rolling, and the filtering precision reaches 3 microns.
5. The production method of a small-caliber thick-wall titanium alloy seamless tube according to claim 1, characterized in that: in the third step, after each pass of cold rolling of the titanium alloy pipe, taking a 100mm long pipe section sample, removing the wall thickness of the pipe section sample by acid washing by 0.01mm, cutting open and observing the inner and outer surfaces, confirming the distribution, the trend and the maximum defect position of crack defects, taking longitudinal and transverse metallographic structure samples at the maximum defect position, determining the maximum depth of the crack defects to be h and the opening distance for observing the crack defects, removing the crack defects according to the opening distance and the maximum depth h, taking the 100mm long pipe section sample after removing, observing by an imager and a stereomicroscope to confirm that the inner and outer surfaces have no defects, and then carrying out intermediate vacuum annealing and next pass of cold rolling on the titanium alloy pipe;
the inner surface defect with the opening distance of the crack defect being more than or equal to 0.02mm is subjected to inner honing to remove the inner surface wall thickness h +0.02mm of the titanium alloy pipe;
selecting an abrasive belt to remove the wall thickness h +0.02mm of the outer surface of the titanium alloy pipe by outwards polishing the outer surface defect with the opening distance of the crack defect being more than or equal to 0.02mm;
and selecting inner and outer surface flowing acid cleaning for the inner and outer surface defects with the opening distance of the crack defect less than 0.02mm, and removing the wall thickness h +0.02mm of the titanium alloy pipe.
6. The production method of a small-caliber thick-wall titanium alloy seamless tube according to claim 5, characterized in that: in the third step, the inner honing adopts green carborundum oilstone with W40 granularity bonded by resin bonding agent, the working pressure is 1.3Mpa, and the honing speed is 18-21 m per minute; the single inner surface flow pickling adopts plastic bags to cover the outer surface of the titanium alloy pipe in a bundling manner, and the single outer surface flow pickling adopts plastic to block two end heads of the titanium alloy pipe;
the pickling solution adopts HF acid: HNO 3 Acid: water is added according to the weight ratio of 4:15:81 weight percent, and flowing through the inner surface and/or the outer surface of the titanium alloy pipe at a speed of more than or equal to 3 m/min.
7. The production method of a small-caliber thick-wall titanium alloy seamless tube according to claim 1, characterized in that: in the third step, the deformation rate epsilon and the K value of each cold rolling pass in the cold rolling process are smaller than those of the previous cold rolling pass, and the K value of each cold rolling pass is more than or equal to 1;
the titanium alloy pipe with the outer diameter Da and the wall thickness Sa is cold-rolled into a titanium alloy pipe with the outer diameter Db and the wall thickness Sb for one pass, and the deformation rate epsilon of the cold rolling for the pass is calculated by the following formula:
ε＝((Da-Sa)×Sa-(Db-Sb)×Sb)/((Da-Sa)×Sa)；
the calculation formula of the K value of the pass cold rolling is as follows: k = (Sa-Sb) × Da/(Da-Db) × Sa.
8. The production method of a small-caliber thick-wall titanium alloy seamless tube according to claim 7, characterized in that: in the third step, the intermediate vacuum annealing process of the titanium alloy pipe with the deformation rate of epsilon and the outer diameter of Db and the wall thickness of Sb is as follows: the temperature rising speed is 2 ℃/min, the intermediate annealing temperature is (600 +300 multiplied by epsilon) DEG C, the heat preservation time is 55 multiplied by Sb minutes, and the elongation of the annealed titanium alloy tube is more than or equal to 30 percent.
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| CN117548520A (en) * | 2024-01-12 | 2024-02-13 | 成都先进金属材料产业技术研究院股份有限公司 | Titanium alloy seamless tube and method for improving plasticity of thin-wall titanium alloy seamless tube |
| WO2024087681A1 (en) * | 2022-10-25 | 2024-05-02 | 成都先进金属材料产业技术研究院股份有限公司 | Method for improving flattening performance of titanium alloy seamless tube |
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| WO2024087681A1 (en) * | 2022-10-25 | 2024-05-02 | 成都先进金属材料产业技术研究院股份有限公司 | Method for improving flattening performance of titanium alloy seamless tube |
| CN117102273A (en) * | 2023-10-24 | 2023-11-24 | 成都先进金属材料产业技术研究院股份有限公司 | Titanium alloy seamless pipe and method for improving rotation bending fatigue performance thereof |
| CN117102273B (en) * | 2023-10-24 | 2024-02-02 | 成都先进金属材料产业技术研究院股份有限公司 | Titanium alloy seamless pipe and method for improving rotation bending fatigue performance thereof |
| CN117548520A (en) * | 2024-01-12 | 2024-02-13 | 成都先进金属材料产业技术研究院股份有限公司 | Titanium alloy seamless tube and method for improving plasticity of thin-wall titanium alloy seamless tube |
| CN117548520B (en) * | 2024-01-12 | 2024-04-19 | 成都先进金属材料产业技术研究院股份有限公司 | Titanium alloy seamless tube and method for improving plasticity of thin-wall titanium alloy seamless tube |
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